Completely different, but something that makes me just as happy: This video of voiceless talking hits me as hard as the first time I saw the multi-touch demo from the TED conference in Monterey.

Being able to help people with ALS in the near term rocks. The longterm potential for hardcore geeks is just icing. (Imagine how frustrating it'd be for teachers when their students are collaborating during tests without looking, moving or talking!)